rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6256/1:b..l P5773/1:b..l rcu: (detected by 0, t=10502 jiffies, g=30321, q=210 ncpus=2) task:syz-executor state:R running task stack:21608 pid:5773 ppid:5769 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 unwind_next_frame+0x200f/0x2970 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 save_stack+0x125/0x230 mm/page_owner.c:128 __reset_page_owner+0x4e/0x190 mm/page_owner.c:149 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1181 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365 free_unref_page_list+0xbe/0x860 mm/page_alloc.c:2504 release_pages+0x1f7a/0x2200 mm/swap.c:1022 __folio_batch_release+0x71/0xe0 mm/swap.c:1042 folio_batch_release include/linux/pagevec.h:83 [inline] shmem_undo_range+0x630/0x1b20 mm/shmem.c:1026 shmem_truncate_range mm/shmem.c:1135 [inline] shmem_evict_inode+0x245/0x9e0 mm/shmem.c:1264 evict+0x4ca/0x8d0 fs/inode.c:705 do_unlinkat+0x38c/0x590 fs/namei.c:4406 __do_sys_unlink fs/namei.c:4447 [inline] __se_sys_unlink fs/namei.c:4445 [inline] __x64_sys_unlink+0x49/0x50 fs/namei.c:4445 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f2db8b99fa7 RSP: 002b:00007fff6a706a98 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2db8b99fa7 RDX: 00007fff6a706ac0 RSI: 00007fff6a706b50 RDI: 00007fff6a706b50 RBP: 00007fff6a706b50 R08: 00007fff6a707b50 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007fff6a707be0 R13: 00007f2db8c0471f R14: 00000000000654d0 R15: 00007fff6a707c20 task:syz-executor state:R running task stack:20936 pid:6256 ppid:6243 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x0/0x80 kernel/kcov.c:321 Code: c0 4c 89 01 48 c7 44 11 08 05 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 0f 1e fa 48 8b 04 24 65 48 8b 0d c0 9c 7c 7e 65 8b 15 c1 9c 7c RSP: 0018:ffffc9000559f3e0 EFLAGS: 00000246 RAX: ffffffff81bad28a RBX: ffffc9000559f4a0 RCX: ffff88802ba48000 RDX: 0000000000000000 RSI: ffffffff81bad28a RDI: 0000000000000000 RBP: ffffc9000559f470 R08: ffff88802ba48000 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff81bad28a R13: 1ffff110057490ae R14: ffffffff8175b850 R15: ffffc9000559f3e8 arch_stack_walk+0x12a/0x190 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 save_stack+0x125/0x230 mm/page_owner.c:128 __reset_page_owner+0x4e/0x190 mm/page_owner.c:149 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1181 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365 free_unref_page_list+0xbe/0x860 mm/page_alloc.c:2504 release_pages+0x1f7a/0x2200 mm/swap.c:1022 __folio_batch_release+0x71/0xe0 mm/swap.c:1042 folio_batch_release include/linux/pagevec.h:83 [inline] shmem_undo_range+0x630/0x1b20 mm/shmem.c:1026 shmem_truncate_range mm/shmem.c:1135 [inline] shmem_evict_inode+0x245/0x9e0 mm/shmem.c:1264 evict+0x4ca/0x8d0 fs/inode.c:705 do_unlinkat+0x38c/0x590 fs/namei.c:4406 __do_sys_unlink fs/namei.c:4447 [inline] __se_sys_unlink fs/namei.c:4445 [inline] __x64_sys_unlink+0x49/0x50 fs/namei.c:4445 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4d0d199fa7 RSP: 002b:00007ffc0f9232c8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4d0d199fa7 RDX: 00007ffc0f9232f0 RSI: 00007ffc0f923380 RDI: 00007ffc0f923380 RBP: 00007ffc0f923380 R08: 00007ffc0f924380 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffc0f924410 R13: 00007f4d0d20471f R14: 0000000000063ae5 R15: 00007ffc0f924450 rcu: rcu_preempt kthread starved for 10591 jiffies! g30321 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:27656 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__asan_memset+0x5/0x40 mm/kasan/shadow.c:83 Code: 0f 1f 44 00 00 f3 0f 1e fa 89 f6 48 8b 0c 24 ba 01 00 00 00 e9 bc ea ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 55 <41> 56 53 48 89 d3 89 f5 49 89 fe 48 8b 4c 24 18 48 89 d6 ba 01 00 RSP: 0018:ffffc90000007328 EFLAGS: 00000246 RAX: ffffc90000007540 RBX: ffffc90000007440 RCX: ffffffff8ce93440 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90000007458 RBP: ffffc90000007458 R08: ffffffff8ce93440 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000100 R12: ffffc90000007408 R13: dffffc0000000000 R14: ffffffff81df100e R15: ffffffff8f11979c FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3b3376 CR3: 000000006b984000 CR4: 00000000003506f0 Call Trace: unwind_next_frame+0x1648/0x2970 arch/x86/kernel/unwind_orc.c:592 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] kmem_cache_alloc_node+0x14c/0x320 mm/slub.c:3540 kmalloc_reserve+0x95/0x240 net/core/skbuff.c:562 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653 skb_copy+0x13d/0x7a0 net/core/skbuff.c:1987 mac80211_hwsim_tx_frame_no_nl+0xca9/0x11a0 drivers/net/wireless/virtual/mac80211_hwsim.c:1840 mac80211_hwsim_tx_frame+0x1b5/0x200 drivers/net/wireless/virtual/mac80211_hwsim.c:2176 mac80211_hwsim_beacon_tx+0x3e9/0x780 drivers/net/wireless/virtual/mac80211_hwsim.c:2269 __iterate_interfaces+0x243/0x500 net/mac80211/util.c:766 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:802 mac80211_hwsim_beacon+0xbb/0x1b0 drivers/net/wireless/virtual/mac80211_hwsim.c:2295 __run_hrtimer kernel/time/hrtimer.c:1750 [inline] __hrtimer_run_queues+0x52a/0xc40 kernel/time/hrtimer.c:1814 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1831 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148 Code: f8 22 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 33 02 44 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2e 41 89 de 80 RSP: 0018:ffffffff8ce07d80 EFLAGS: 000002c2 RAX: fd174193fe5ff400 RBX: ffffffff8162a490 RCX: fd174193fe5ff400 RDX: 0000000000000001 RSI: ffffffff8acac900 RDI: ffffffff8b1c81e0 RBP: ffffffff8ce07eb8 R08: ffff8880b8e36b2b R09: 1ffff110171c6d65 R10: dffffc0000000000 R11: ffffed10171c6d66 R12: 1ffffffff19d2688 R13: 1ffffffff19c0fbc R14: 0000000000000000 R15: dffffc0000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:753 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97 cpuidle_idle_call kernel/sched/idle.c:170 [inline] do_idle+0x1f0/0x4e0 kernel/sched/idle.c:282 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380 rest_init+0x2e2/0x300 init/main.c:744 arch_call_rest_init+0xe/0x10 init/main.c:841 start_kernel+0x459/0x4e0 init/main.c:1086 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555 x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536 secondary_startup_64_no_verify+0x179/0x17b